ajax for asp.net2.0中'Sys' is undefined的原因及解决方案

当运行一个asp.net 2.0 ajax web页面或为一个已经存在的web应用程序启用Ajax功能时，原来正确的页面，可能会出现提示“ 'Sys' is undefined “。

引起的原因有很多，最可能的一种是： 在页面上启用Ajax功能，但没有在web.config文件中增加相应的配置。

解决方案：

先新建一个普通的vs2005 web 项目， 查看默认的web.config文件，内容大致如下：

Code <!-- {cps..0}--><? xmlversion="1.0"encoding="utf-8" ?> < configuration > < appSettings /> < connectionStrings /> < system.web > < compilation debug ="true" /> < authentication mode ="Windows" /> </ system.web > </ configuration >

然后，再新建一个ASP.NET AJAX-enabled Web site，查看默认的web.config文件，内容大致如下：

Code <!-- {cps..1}--><? xmlversion="1.0" ?> < configuration > < configSections > < sectionGroup name ="system.web.extensions" type ="System.Web.Configuration.SystemWebExtensionsSectionGroup,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" > < sectionGroup name ="scripting" type ="System.Web.Configuration.ScriptingSectionGroup,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" > < section name ="scriptResourceHandler" type ="System.Web.Configuration.ScriptingScriptResourceHandlerSection,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" requirePermission ="false" allowDefinition ="MachineToApplication" /> < sectionGroup name ="webServices" type ="System.Web.Configuration.ScriptingWebServicesSectionGroup,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" > < section name ="jsonSerialization" type ="System.Web.Configuration.ScriptingJsonSerializationSection,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" requirePermission ="false" allowDefinition ="Everywhere" /> < section name ="profileService" type ="System.Web.Configuration.ScriptingProfileServiceSection,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" requirePermission ="false" allowDefinition ="MachineToApplication" /> < section name ="authenticationService" type ="System.Web.Configuration.ScriptingAuthenticationServiceSection,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" requirePermission ="false" allowDefinition ="MachineToApplication" /> </ sectionGroup > </ sectionGroup > </ sectionGroup > </ configSections > < system.web > < pages > < controls > < add tagPrefix ="asp" namespace ="System.Web.UI" assembly ="System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" /> </ controls > </ pages > < compilation debug ="false" > < assemblies > < add assembly ="System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" /> </ assemblies > </ compilation > < httpHandlers > < remove verb ="*" path ="*.asmx" /> < add verb ="*" path ="*.asmx" validate ="false" type ="System.Web.Script.Services.ScriptHandlerFactory,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" /> < add verb ="*" path ="*_AppService.axd" validate ="false" type ="System.Web.Script.Services.ScriptHandlerFactory,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" /> < add verb ="GET,HEAD" path ="ScriptResource.axd" type ="System.Web.Handlers.ScriptResourceHandler,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" validate ="false" /> </ httpHandlers > < httpModules > < add name ="ScriptModule" type ="System.Web.Handlers.ScriptModule,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" /> </ httpModules > </ system.web > < system.web.extensions > < scripting > < webServices > </ webServices > </ scripting > </ system.web.extensions > < system.webServer > < validation validateIntegratedModeConfiguration ="false" /> < modules > < add name ="ScriptModule" preCondition ="integratedMode" type ="System.Web.Handlers.ScriptModule,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" /> </ modules > < handlers > < remove name ="WebServiceHandlerFactory-Integrated" /> < add name ="ScriptHandlerFactory" verb ="*" path ="*.asmx" preCondition ="integratedMode" type ="System.Web.Script.Services.ScriptHandlerFactory,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" /> < add name ="ScriptHandlerFactoryAppServices" verb ="*" path ="*_AppService.axd" preCondition ="integratedMode" type ="System.Web.Script.Services.ScriptHandlerFactory,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" /> < add name ="ScriptResource" preCondition ="integratedMode" verb ="GET,HEAD" path ="ScriptResource.axd" type ="System.Web.Handlers.ScriptResourceHandler,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35" /> </ handlers > </ system.webServer > </ configuration >

注意：用后一个web.config文件替换前一个web.config文件，或者将后一个文件的新增部分添加到前一个项目中的web.config文件即可。 主要是粗体部分

<?xml version="1.0"?> <configuration> <configSections> <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"> <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"> <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/> <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"> <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere" /> <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" /> <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" /> </sectionGroup> </sectionGroup> </sectionGroup> </configSections> <system.web> <pages> <controls> <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> </controls> </pages> <compilation debug="false"> <assemblies> <add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> </assemblies> </compilation> <httpHandlers> <remove verb="*" path="*.asmx"/> <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/> </httpHandlers> <httpModules> <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> </httpModules> </system.web> <system.web.extensions> <scripting> <webServices> </webServices> </scripting> </system.web.extensions> <system.webServer> <validation validateIntegratedModeConfiguration="false"/> <modules> <add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> </modules> <handlers> <remove name="WebServiceHandlerFactory-Integrated" /> <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/> <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" /> </handlers> </system.webServer> </configuration>